The proposed collaboration study between Ms. Usaneya Perngparn, Chulalongkorn University, Thailand and Dr. Nemoto, Public Health Institute, California, will investigate the sociocultural contexts of HIV risk behaviors and drug use among Thai female and male-to-female transgender (kathoey) sex workers in Bangkok. The national campaign of 100% condom use implemented in 1989 has been successful in reducing new HIV/STIs. However, recent studies indicated low levels of consistent condom use among sexually active young men and women and high HIV sero-prevalence rates among high risk populations, such as direct female sex workers, drug users, MSM, and male and kathoey sex workers. In Thailand, kathoey have been historically accepted because of the karmic idea in Buddhism. Currently, many kathoey engage in sex work. A recent study reported high HIV sero-prevalence rates among kathoey, particularly those who had engaged in sex work (17%). Despite the high HIV/STI sero-prevalence rates and HIV risk behaviors among female and kathoey sex workers in Thailand, very few studies have investigated the sociocultural factors in relation to their HIV risk behaviors, such as their work venues and environment, fatalism, economic pressure to survive and send money to their families, and coping mechanisms to avoid HIV/STI infection and violence from customers. Research is needed to develop theoretical HIV prevention models which include the sociocultural factors specific to female and kathoey sex workers in order to curb future HIV/STIs. The proposed study will conduct a total of 60 qualitative interviews with female and kathoey sex workers (36 female and 24 kathoey) who will be recruited from the targeted work venues in Bangkok (bars/clubs, massage parlors, and street). The specific aims of the study are: 1) To understand substance use and HIV risk behaviors among female and kathoey sex workers specific to their work environment, and describe and explore sociocultural factors which would influence their substance use and HIV risk behaviors, 2) To describe the sociocultural factors of inception of substance use and addiction to substances among female and kathoey sex workers in relation to background variables, 3) To describe substance use and HIV risk behaviors in relation to gender confirmation and feminization surgeries and hormone use among kathoey sex workers, 4) To explore the theoretical models for future substance abuse and HIV/STI prevention studies among female and kathoey sex workers by integrating qualitative and quantitative findings and community input, and 5) To disseminate study findings through professional meetings and publications and the networks of the Community Advisory Board members. PUBLIC HEALTH RELEVANCE: The proposed study will investigate the social, cultural, and environmental factors which influence substance use and HIV risk behaviors among female and transgender female (kathoey) sex workers who work at bars/clubs and massage parlors, and on the street in Bangkok, Thailand. Recent studies show the high HIV/STI infection rates and illegal drug use among these sex workers. The results of the proposed study will help to develop substance abuse and HIV/STI prevention intervention programs which will be culturally appropriate to Thai female and kathoey sex workers. Internationally, studies are needed on how to translate and adapt interventions that have proven to be effective in the U.S. to other communities and international settings, and to learn from other conditions and cultures to inform our understanding of the causes, consequences, and differences in HIV-related risks, morbidity, and mortality in diverse populations.